How to make your own decorative window box.

Here are directions:

Make a Box

Step 1: Lay out the length of the front/back (A), pickets (B), bottom supports (C), ends (D), and bottom (E) on the cedar boards (Cutting List & Diagram). Cut the parts to length and sand the smooth faces with 120-grit sandpaper; leave the rough surface of the cedar as is.

Step 2: Lay out the pickets, smooth surface down, with the ends aligned. Space the pickets evenly (Drawing 1, Project Diagram).
Place the front (A) on the pickets with the edges of the two outside
pickets extending 7⁄8" beyond each end of the front. Drill countersunk
pilot holes for the screws and secure the front to the pickets.